mirror of
https://github.com/onyx-and-iris/grokking-algorithms.git
synced 2024-11-15 17:30:52 +00:00
59 lines
1.4 KiB
Python
59 lines
1.4 KiB
Python
import logging
|
|
from dataclasses import dataclass
|
|
|
|
from tabulate import tabulate
|
|
|
|
logging.basicConfig(
|
|
level=logging.DEBUG,
|
|
format="%(asctime)s %(levelname)s\n\r%(message)s",
|
|
datefmt="%H:%M:%S",
|
|
)
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
@dataclass
|
|
class Item:
|
|
name: str
|
|
value: int
|
|
weight: int
|
|
|
|
|
|
def dynamic(W, items, n):
|
|
# create table and zero fill it (required for calculations)
|
|
table = [[0 for _ in range(W + 1)] for _ in range(n + 1)]
|
|
|
|
# calcalate all possible max values for items in knapsack
|
|
for i in range(1, n + 1):
|
|
for w in range(1, W + 1):
|
|
if items[i - 1].weight <= w:
|
|
table[i][w] = max(
|
|
items[i - 1].value + table[i - 1][w - items[i - 1].weight],
|
|
table[i - 1][w],
|
|
)
|
|
else:
|
|
table[i][w] = table[i - 1][w]
|
|
|
|
format_and_print(table)
|
|
|
|
return table[-1][-1]
|
|
|
|
|
|
def format_and_print(table):
|
|
# enumerate first row (headings) + label each row in column0
|
|
for i, row in enumerate(table):
|
|
if i == 0:
|
|
continue
|
|
row[0] = items[i - 1].name
|
|
table[0] = [i for i in range(W + 1)]
|
|
table[0][0] = None
|
|
|
|
# print tabularised 2D array
|
|
logger.info(tabulate(table, tablefmt="pretty"))
|
|
|
|
|
|
items = [Item("Guitar", 1500, 1), Item("Stereo", 3000, 4), Item("Laptop", 2000, 3)]
|
|
W = 4
|
|
greatest_value = dynamic(W, items, len(items))
|
|
|
|
print(greatest_value)
|